Half kilogram of shabu placed in a plastic bag has been confiscated to the suspects.

Based on the report, the suspects arrived in the NAIA last week.

According to the Bureau of Immigration (BI), three of the four suspects are first-timers in the Philippines; one or two of them possibly chemists of the clandestine laboratory, in the interview of ABS- CBN.

The police believed they are manufacturing a shabu in the middle of the sea.

Authorities said they will investigate whether the vessel is connected to the P1-B worth of shabu recovered in Claveria, Cagayan just last week.